A wall heating in the outer wall


More and more wall heaters are used. Conventionally, the wall heating is mounted in the outer wall. What should be noted here, you can read here.

Wall heating modern, but not always suitable

There have been significant changes in heating technology in recent years. In particular, the wall heating is due to its high potential savings more and more often in focus.

The wall heating should be installed for different reasons, preferably in the outer wall, but this can again lead to disadvantages. What has to be considered with a wall heating in the outer wall, we have discussed below for you.

Functional principle of wall heating

Unlike most heaters (radiators with hot water supply), heating is based on a different physical principle. Conventional radiators heat the air, which is why they are also known as convection heaters. Wall heaters, on the other hand, rely on the principle of radiant heat. It is not the air, but the illuminated body is heated. As bring various advantages:

  • less dust turbulence (interesting for asthmatics and allergy sufferers)
  • more comfortable and comfortable warmth
  • if properly used significantly lower heating costs

Energy saving potential in principle

Thanks to the radiant heat, a room can be heated to 18 degrees, yet people feel these temperatures as 21 degrees. In addition, per degree of further heating of the room air via a convection heating the additional expenditure of energy amounts to six to seven per cent.

The path of heat with wall heating in interior or exterior wall

From the technically necessary structure but also disadvantages. So the wall heater should preferably be laid in he outer wall. This also has very simple physical reasons. In particular, the facts that cold air sinks and warm air rises, should be noted.

Suppose the wall heater were in the interior wall. Then the warm air would take the following "path": the warm air rises in the room. She inevitably pulls to the coldest wall, as here creates a strong downward flow. Because the warm air is cooled down on the coldest wall. In an old building without contemporary insulation, the U-value of the wall can be extremely disadvantageous.

This will cool the air faster and stronger. At the same time the cold air on the floor is sucked in again in the area of ​​the wall heating, since here the warm air rises upwards. In the foot and leg area, therefore, results in a permanent cold breeze, which can be extremely unpleasant. Therefore, the wall heater should preferably be mounted on the outer wall.

The thermal insulation of the outer wall is crucial

Here, however, efficiency and thus potential energy savings result from the thermal insulation. Especially behind the wall heating a very good thermal insulation has to be mounted. Thicker plaster before wall heating is not recommended. Although these would store the heat well, but the heating is significantly slower in the effect.

With poor external insulation a lot of heat is radiated to the outside. Therefore, the flow temperature must be increased, which is reflected again in higher heating costs. Therefore, the wall heating in the old building without appropriate insulation is disadvantageous accordingly.

Other factors to consider when wall heating in the outer wall

Basically, could be avoided on the inner walls. But then arises especially in uninsulated, very cold outer walls, the problem of constantly cold feet. But another aspect is important.

The window area must also be taken into account or deducted from the possible area for wall heating, especially in the case of an outer wall. However, due to the used radiant heat, the design of the wall heating must be correspondingly large area.

Tips & Tricks

The wall heating in the old building is especially worthwhile if it is insulated accordingly. As already stated, the insulation should be behind the wall heating in the outer wall or right outside the façade as a thermal insulation composite system (ETICS).

Artikelbild: Radovan1 / Shutterstock


Video Board: How to insulate a walls; step by step - part 1